Pallets are platforms for supporting weight thereon, and by which materials, packages, or goods that are stacked thereon may be handled, stored and/or moved. Goods positioned on pallets are typically moved and stored in warehouses, factories, or vehicles, for example, by forklift equipment, in which the forklift tines are inserted into channels in the pallet or by way of engagement with an undersurface of a top deck of the pallet.
Pallets have traditionally been formed from wood, plastic and various composite materials. Wood pallets, however, are subject to breakage and difficult to obtain and maintain in a sanitary condition. In environments where sanitation is important, such as in the food industry, pallets may be of limited usefulness. From time to time, the wood used in pallets is also known to contain eggs or actual insects thereby causing problematic infestations. Plastic pallets are bulky and initially, may be very expensive. Wood or plastic pallets are typically provided in a fully erected or constructed state and not deconstructed when not in use and therefore always require a maximum amount of space.
A variety of cardboard or pallets that are erectable and collapsible have been suggested. The following discusses some of these.
U.S. Pat. No. 2,944,296 to Hamilton describes a pallet consisting of a plurality of channels which are made from folded cardboard or the like and which include slots through which wooden slats are inserted to create a basic pallet lattice structure. The Hamilton type pallet is made of independent channels that are free floating relative to one another, are not pre-aligned with respect to the distances between each of the channels and do not appear to always be maintainable in parallel. Additionally, when the Hamilton type pallet is in use, the channels may move thereby creating some risk of tipping. Thus, while the Hamilton pallet uses a substantially smaller amount of wood, the complexity of the arrangement creates risks that are not inherent in the conventional nailed pallet design.
U.S. Pat. No. 2,444,183 to Cahners describes a fiber board portable platform which includes the formation of channels from folded cardboard and their interlocked relationship including the use of cross members located within the channels to enhance support. While the fiberboard platform of Cahners does allow for formation out of fiberboard without the need for any nailing, the Cahners' channels are formed in one direction with no support members at right angles thereto other than the flat cardboard surfaces. Thus, if the weight load is shifted onto, for example, two out of three of the channels of this type of fiberboard portable platform, the lifting of the pallet with a forklift may cause the cardboard flat surface to fold and the structural integrity of the platform itself to be permanently damaged.
U.S. Pat. No. 4,378,743 to McFarland describes a paperboard pallet having interlocking runners. However, this pallet is tray-like wherein the runners are inserted into the bottom, i.e., are located above and not below the basic horizontal surface, and are inserted by the use of blocks located at the bottom of the channels. However, as with the prior art described above, the runners are all in a single direction and only the tray cardboard sidewalls provide for structural support at right angles to the runners. Additionally, forklift motion or other motion of the McFarland type pallet may cause the blocks to pop up through the base and therefore destroy the integrity of the structure itself. Additionally, the shifting of weight or movement of the McFarland pallet such that force is applied to the areas of the pallet where there is no significant weight may cause a folding to occur at points parallel to the runners.
U.S. Pat. No. 3,308,772 describes a disposal pallet having basically U-shaped channels formed of sheet material located on the underside, This type of pallet does not allow for significant structural support at right angles to the parallel channel. Additionally, the pallet channels themselves are hollow and subjecting the pallet to weight may cause flattening, and therefore destruction of the basic integrity of the pallet.
U.S. Pat. No. 4,185,565 to Nymoen describes sheet material type pallets having a base with parallel channels on the underside. The Nymoen parallel channels are initially formed by a series of folds from a single under sheet that are interlocked with hollow channels formed at the ends of a second base sheet. The result is a pallet which has channels that are hollow but with closed ends. Both the flattening problems as well as the problems of bending at points between the channels may occur with this type of design.
U.S. Pat. No. 4,091,923 is directed to a combined carton and supporting pallet. This particular design involves a typical cardboard box, and more specifically a synthetic pallet with a base in the flap, the flap being tucked into the folding flaps of the typical box and the base positioned over it. The box as turned over rests on sections or channels, which are attached to the bottom of the base. This particular type of pallet does not teach any structural support at right angles to the runners located on the bottom and is fully functional when it is located in place in a particular carton for which it is designed to fit. In other words, the pallet described in this patent is unique to a particular size carton but yet is not an integral part thereof and must be inserted into the carton. If the pallet of this patent is used without being inserted into a carton, it appears to be even less structurally dependable than the other pallets cited above due to the fact that one of the two top layers is a free floating flap. Also, the lack of structural support—other than the single piece of cardboard which would bind the runners at right angles to the runners—reduces its structural dependability.
U.S. Pat. No. 2,494,730 to Thursby describes palletized containers, which rely upon folded cardboard channels, and inserts. The Thursby containers lack any additional structural support other than cardboard at right angles to the channels.
U.S. Pat. No. 4,863,024 to Booth is directed to a collapsible pallet. The Booth pallet has a base sheet with side edges foldable into U-type runner channels and further folded to form under supports resting under the base sheet. Because of what appears to be the excessively large size of the Booth base sheet, the Booth pallet is difficult to store, manipulate and assemble. For example, an assembled standard 40″×48″ pallet would require a Booth base sheet on the order of at least 80″, not including the material necessary for forming the channels. Because of the size, the Booth pallet also requires more than one person to assemble the unit plus space large enough to accommodate the Booth pallet materials in order to assemble the pallet. Booth does not describe rackability as a feature. A further disadvantage is the shown type of friction lock, which is easily collapsible due to vibration or movement or heavy weight loads.
While it can be seen that a number of attempts have been made to design inexpensive, but structural dependable pallets, there continues to be a need for improvements in both cost, ease of use, and overall strength. The present invention satisfies this need.